| Building a fact table in Oracle 10G [message #155192] |
Thu, 12 January 2006 15:23  |
selectsplat
Messages: 2
Registered: January 2006
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Junior Member |
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Greetings.
I'm a long time Data Warehouse developer, however, I've very new to Oracle.The process of building a fact table for a star schema in SQL Server or Sybase goes something like this...
- Update your dimension tables.
- Select all of the values from the various tables in the staging areas you want to go into your fact table.
- Cycle through each column in the fact table, join to the cooresponding dimension table, and replace the 'value' with they 'key' from the dimension, so that you end up with a fact table of nothing buy key values.
During the process of this last step, I normally create a series of #temp tables, one for each step of the way. However, I am told that in Oracle, you don't create temp table, but just join all tables together at once.
My question is, do I still use this same process, except instead of replacing one column at a time, just do them all at once? And, should I keep this as two steps, first gatehr the column I want from the stage, then replace all the values from the dimensions, or should I do all of this in one step?
Thnaks in advance.
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| Re: Building a fact table in Oracle 10G [message #159143 is a reply to message #155192] |
Thu, 16 February 2006 06:34  |
selectsplat
Messages: 2
Registered: January 2006
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Junior Member |
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Thanks for the response, but it doens't really answer my question.
In orderable, am I supposed to replace the value for keys for all dimansions at once, even if I have 30 some dimensions?
IN SQL Server, I'd do one at a time, in a series of temp tables. In oracle, I'm told not to use temp tables, but a 30 table join does sounds like the most efficient way to do things.
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